|
Overview |
|
|
|
Group |
|
|
|
Quick Info
Windows NT
| Yes
| Win95
| No
| Win32s
| No
| Import Library
| user-defined
| Header File
| winuser.h
| Unicode
| No
| Platform Notes
| HOOKPROC
|
|
|
DebugProc
The DebugProc hook procedure is an application-defined or library-defined callback function
that Windows calls before calling the hook procedures associated with any
other type of hook. The system passes information about the hook to be called to
the DebugProc hook procedure, which examines the information and determines whether to
allow the hook to be called.
LRESULT CALLBACK DebugProc(
int nCode,
| // hook code
| WPARAM wParam,
| // type of hook about to be called
| LPARAM lParam
| // address of structure with debugging information
| );
|
|
Parameters
nCode
Specifies whether the hook procedure must process the message. If nCode is HC_ACTION, the hook procedure must process the message. If nCode is less than zero, the hook procedure must pass the message to the CallNextHookEx function without further processing and should return the value returned by CallNextHookEx.
wParam
Specifies the type of hook about to be called. This parameter can be one of
the following values:
Value
| Description
| WH_CALLWNDPROC
| Installs a hook procedure that monitors messages sent to a window procedure.
For more information, see the description of the CallWndProc hook procedure.
| WH_CALLWNDPROCRET
| Installs a hook procedure that monitors messages that have just been processed
by a window procedure. For more information, see the description of the CallWndRetProc hook procedure.
| WH_CBT
| Installs a hook procedure that receives notifications useful to a
computer-based training (CBT) application. For more information, see the description of the CBTProc hook procedure.
| WH_DEBUG
| Installs a hook procedure useful for debugging other hook procedures. For more
information, see the description of the DebugProc hook procedure.
| WH_GETMESSAGE
| Installs a hook procedure that monitors messages posted to a message queue.
For more information, see the description of the GetMsgProc hook procedure.
| WH_JOURNALPLAYBACK
| Installs a hook procedure that posts messages previously recorded by a
WH_JOURNALRECORD hook procedure. For more information, see the description of the JournalPlaybackProc hook procedure.
| WH_JOURNALRECORD
| Installs a hook procedure that records input messages posted to the system
message queue. This hook is useful for recording macros. For more information, see
the description of the JournalRecordProc hook procedure.
| WH_KEYBOARD
| Installs a hook procedure that monitors keystroke messages. For more
information, see the description of the KeyboardProc hook procedure.
| WH_MOUSE
| Installs a hook procedure that monitors mouse messages. For more information,
see the description of the MouseProc hook procedure.
| WH_MSGFILTER
| Installs a hook procedure that monitors messages generated as a result of an
input event in a dialog box, message box, menu, or scroll bar. The hook
procedure monitors these messages only for the application that installed the hook
procedure. For more information, see the description of the MessageProc hook procedure.
| WH_SHELL
| Installs a hook procedure that receives notifications useful to a shell
application. For more information, see the description of the ShellProc hook procedure.
| WH_SYSMSGFILTER
| Installs a hook procedure that monitors messages generated as a result of an
input event in a dialog box, message box, menu, or scroll bar. The hook
procedure monitors these messages for all applications in the system. For more
information, see the description of the SysMsgProc hook procedure.
|
lParam
Points to a DEBUGHOOKINFO structure that contains the parameters to be passed to the destination hook
procedure.
Return Values
To prevent the system from calling the hook, the return value must be a
nonzero value. Otherwise, the hook procedure must pass the hook information to the CallNextHookEx function.
Remarks
An application installs this hook procedure by specifying the WH_DEBUG hook
type and the pointer to the hook procedure in a call to the SetWindowsHookEx function.
CallWndProc and CallWndRetProc are placeholders for the application-defined or library-defined function
names.
See Also
CallNextHookEx, CallWndProc, CallWndRetProc, CBTProc, DEBUGHOOKINFO, GetMsgProc, JournalPlaybackProc, JournalRecordProc, KeyboardProc, MessageProc, MouseProc, SetWindowsHookEx, ShellProc, SysMsgProc
| Last news from Greatis Software |
 |
|
Nostalgia .Net |
|
.Net is powerful, but not all-powerful, so sometimes we need to use Win32 API for our .Net applications. It's simple enough with Platform Invoke if you have Win32 skill, but we do not always have time to dig the ancient documentation, declare the special types that are compatible with Win32, find the values of the Win32's constants and so on. Nostalgia .Net offers several simple-to-use classes, and components that will allow you to forget about the headache of Win32 and just use the power of Win32 in your application the same way as you use the native. Net classes. More » |
| Recommended software for developers |
 |
|
Ultimate Pack |
|
Component pack for Delphi and C++ Builder that contains runtime form designer, runtime object inspector, print suite and much more for the very special price. More » |
 |
|
Form Designer .Net |
|
Unique runtime form design solution that allows to edit any form in .Net WinForms application at runtime with full source codes for only 300 euro! More » |
 |
|
Print Suite .Net |
|
Print Suite .Net is a set of components for easy printing texts, images and grids from your WinForms applications. Full C# source codes are available More » |
 |
|
Gradient Controls .Net |
|
Gradient Controls .Net offers controls with gradient background feature. Labels, panels and so on... Full C# source codes are available More » |
 |
|
Greatis iGrid |
|
iGrid plots drawing grid right over your desktop, so you can use it everywhere, with any drawing application without any special plugins for different graphic editors. More » |
All the contacts and projectsDmitry Vasiliev (just.dmitry)
Related LinksSoftware for Visual Studio .NET developers
Software for Delphi and C++ Builder developers
Software for Visual Basic 6 developers
Delphi Tips&Tricks
MegaDetailed.NET More Online Helps Win32 Programmer's Reference
Win32 Multimedia Programmer's Reference
OLE Programmer's Reference
Microsoft Windows Pen API Programmer's Reference
Microsoft Windows Sockets 2 Reference
Microsoft Windows Telephony API (TAPI) Programmer's Reference
Unix Manual Pages
|
